ByMatthew ShaerJune 23, 2012

The Google homepage today is adorned an interactive Turing Machine, a gadget often identified as a predecessor to the modern computer. The doodle honors Alan Turing, a British mathematician, cryptanalyst, and the inventor of the Turing Machine. But Turing, who would have turned 100 today, has another, even more important accolade to his name: He helped bring a close to World War II.

In 1938, Turing, already an accomplished mathematician with a doctorate from Princeton, began working with the British Government Communications Headquarters, which was tasked with cracking the infamous Enigma machine. First pressed into use in 1919, the Enigma machine was used to decipher and transmit messages between German commands.

Deciphering the Enigma code, the British correctly believed, would lend them a great advantage over the German war machine, which was then lurching into gear. As David Leavitt of the Washington Post notes, "because the [Engima] code was generated by a machine, Turing decided, only a machine could break it." Together with a group of the best scientists in England – chief among them Gordon Welchman – he set about building it.

The first "bombe," as the code-cracking machines were known, received the name of "Victory" – the next was dubbed "Aggie," short for Agnus Dei. The machines were installed in Bletchley Park, an estate in Buckinghamshire, England, and quickly put to work. By November of 1942, during the height of the war, there were reportedly 49 bombes in use, all of them dedicated to deciphering German code.

All the information, meanwhile, was collected under the codename Ultra. The project was a wild success: With the help of the machines made by Turing and Welchman, the Allies were finally one step ahead of the Germans – they could track Nazi troop movements and potential U-Boat attacks.